An inspector at a production company is checking the thickness of 300 brew caps produced by two types of machines. A random sample of 12 brew caps produced by both machines yields the following results. Type I Type II Sample Mean 0.222667 0.227333 Sample Standard Deviation 0.00342 0.002839 To conduct a -test for the above data set, which statement is correct? Select all that apply. The thickness of 300 brew caps is known to be normally distributed. The independent variables are the brew caps produced by type I and type II machines. The dependent variable is the thickness of the brew caps. The -value is -8.79. The -value is -3.63